About 1 in 5 samples of retail milk have tested positive for the bird flu virus affecting U.S. livestock and poultry, according to the Food and Drug Administration, though additional research showed that dairy products remain safe for consumption.
Initial results from a national survey of milk found around 20% of samples contained particles of highly pathogenic avian influenza, suggesting the outbreak among dairy herds is more widespread than previously thought. However, preliminary egg inoculation tests, which are considered the "gold standard" in determining whether a virus is infectious, have shown that pasteurization is effective in killing the virus.
The FDA also said that bird flu was not detected in any samples of retail powdered infant formula.
"These results reaffirm our assessment that the commercial milk supply is safe," the agency said in a statement Friday.
Bird flu has been detected in 34 dairy herds across nine states, with Colorado reporting its first positive case on Thursday.
The U.S. has ramped up its response to contain the virus' spread, and on Monday implemented testing requirements for dairy cows before they're transported across state lines. The Animal and Plant Health Inspection Service is also requiring electronic identification for certain cattle and bison moving between states in order to quickly pinpoint and respond to any outbreaks.
The FDA is conducting research on nearly 300 retail samples of dairy products from 38 states, with plans to release additional results as soon as possible.
